Drill chip breaker



F ,5 23 J Qrwe/Mo'n Erik Hallden E HALLDEN DRILL CHIP BREAKER Filed July 21, 1947 March 14}, 1950 Patented Mar. 14, 1950 3,500,177 DlEtllLL crnr BREAKER Erik Hallden, Detroit, Mich., assignor to Ex- Cell-O Corporation, Detroit, Mich, a corporation of Michigan Application July 21, 194.7, Saar No. ram

The invention relates generally to drill chip 7 One object of the invention is to provide an efficient and reliable drill chip breaker of the above general character which is extremely simple in construction, "which has few parts subject to wear and in which internal friction is reduced to a minimum. 7

Another object is to provide a drillchip breaker which is adapted to sustainthe tool supporting spindle. against the cutting action of the tool, and which is operative automatically as. an incident to the rotation of the spindle to periodically relieve the axial thrust on the spindle.

Still another object is to providea drill chip breaker which can be rendered active or inac tive by simple adjustments, thus making it particularly suitable for incorporation in a drilling machine as a permanent part thereof. e

A further object is to provide. a drill chip .6 Claims. (Cl. 77- 33) Whilethe invention is' susceptibleof'various modifications and alternative constructions, I have shown in the drawings and will'herein describe in detail the preferred embodiment, but it is to be understood that I do not'thereby intend to limit the invention to the specific form disclosed, but intend to cover all modifications and alternative constructions falling within the spirit and scope of the invention as expressed in the appended claims.

For purposes of i1lustration,'the improved chip breaker has been shown as installed in a drilling machine of the type having .arotatably driven tool supporting spindle 5 journaled in and movable with an axially translatable quill nonrotatable (in The quill may be supported on the v machine frame in an suitable and well known manner, and is adapted to be translatedaxially. by feed mechanism (not shown) to feed the spin-- dle supported tool into and to retract it from the work.

breaker for drilling machines utilizing antifriction bearing elements coacting with hearing members carried respectivelyby thespin dle and its support for. sustaining the, feeding thrust of the spindle, and having one of the bearing mem bers formed with a series of drop grooves 00- operating. with the bearing elements to moinen--. tarily and periodically relieve the axial thrust.

on the spindle as an incident to its rotation.

Other objects and advantages of. the invention. will become apparent from the following detailed description ofthe preferred embodiment illustrated in the accompanying drawing, in

which: 7 p

Figure 1 is a fragmentary side view of a drilling machine spindle and support. therefor equipped with a drill chip breaker embodying the features of the invention, the chip breaker being.

sectioned longitudinally of the spindle. I

Fig. 2 is a sectional view taken in a plane substantially on the line 2-412 of Fig.1.

Fig. 3 is a sectional view taken in a plane sub stantially on the line 3-3 of Fig. 1. i

Fig. 4 is a sectional View similar to Fig. 3,

showing the chip breaker adjusted to an inactive position.

Fig. 5 is a fragmentarysectional view of the upper bearing member showing the form of one of the drop grooves;

As herein shownpthe spindle 5 is adapted to extend through the quill 6, andis provided at its lower end with an enlarged. head I. having a socket for-holding a cutting tool, such as ,a drill 8. The upper end of the spindle is formed with longitudinal splines B for connection. with the usual driving instrumentalities by which the spindle is rotated.

In accordance with the invention, the im-. proved. chip breaker is, associated with the spiri dlefi and the quill 6 in a manner which enables it to sustain the spindle against the cutting action of the drill as the latter is fed to the work. By reason of its novel construction and. its relationship to the elements of the drilling machine,

the chip breaker is operative automatically as an incident to the rotation of the spindle alternately to project and relieve the spindle relative to the quill in the direction of the feed. lMore H I.

particularly stated, the arrangement is such-H that as the tool is rotated and fed to the work by a uniform feeding movement of the quill 6, thelchip breaker is operative. during a por tion of each revolution of the spindle to exert a feeding thrust on the spindle; causing it to ad,-

vance with the quill. In the succeeding portion of the revolution the. feeding thrust is relieved to permit a momentary dwell or to reduce the rate of advance of the spindlesuificiently to cause the tool to sever the chip curls formed by it during the preceding portion of therevolution.

To accommodate its. chip breaking action, the

spindle 5 is mounted for limited axial movement relative to the quill 6, and. means is proto reduce the drag on the ring as the collarrotates with the spindle.

In the exemplary embodiment ofthe invention, the chip breaker comprises an upper bearing member I5 fixed to and abutting. the lower,

end of the quill 6. and a lower bearing member mounted on and rotatable with the spindle 5.'

As shown in Fig. 1, the lower bearing member 16 is seated against a shoulder 11 formed by the 4 causes the tool 8 to sever the chip curls formed by the tools.

Provision is made for adjusting the chip breaker to an inactive position in which it is inefiective to relieve the spindle in the manner above described in the event that it is desired to operate the drilling machine in a conventional manner. For this purpose, the grooved upper bearing member I5 is constructed so that the spacing or pattern of the grooves 22 may be changed from that of the bearing elements in a manner such that the grooves are not at any time presented for registration simultaneously with all of the bearing elements. Thus, one or more of the bearing elementsis. or are operative at all times to sustain the thrust of the spindle while their companion "bearing elementsare in registration with grooves.

enlarged hea'd '!'of the spindle, The adjacent axial faces of the members 15 and i6 a'reshaped to define opposed annular bearing tracks for a seriesof 'antifriction bearing. elements 20, herein shown as relativelyshort, cylindrical rollers which serve 'to'transmit the 'thrust of the quill 6 to the spindle 5.

To" provide the'intermit'tent" thrust and relief on the spindle 5 for enabling the tool 8 to sever the "chip'urls'fo rmed thereby. the bearing ele-' ments 20 are mounted in a cage 2| provided with a series 6f bearing receiving pockets 'arrangedi in predeterminedangularl'y snacedrelation and ada ted to'n'iainta inthe elements in adefin ite,' fixed pattern astheca'geand elements rotate In-the" exemplary chip breaker, the adjustability is obtained by constructing the upper bearing member in two concentrically arranged parts, namely, an inner ring and. an outer ring 26. The inner ring is mounted on and se-' cured to the quill 6 in any preferred manner, while the outer ring 26 is seated in a recess 21' formed in the outer marginal edge portion of the ring 25. A radially projecting finger piece 28is provided on the outer ring 26 for rotating it relative to the inner ring between the active and inactive positionsdefined by opposed shoulders positioned for coaction with a stop finger 3i fixed incidentto the rotation of 'the lower bearing member; o e-tr the bearing 'tracksfin'thi's instance the track provided by the u per bearing member I5, is formed with a series of 'drop grooves 22 spaced apart simi arly to the spacing of the bearing elements. The grooves 22 vmay berelatively shallow, as for example on the order of 0.013 of aninch in depth, and are formed with, theiredges substantially radial to the rotative axis of the spindle so that the bearing elements 2!] mayenter and leave the grooves at the same instant irres ective of their spacing from the axis of the: spindle,

As hereinshown, the bearing elements and 29 and 30 formed on the base of, the ring 25 and to and rotatable with the outer ring 25. 7 To insure a balanced thrust on the spindle 5 the bearings 20 and grooves 22 are arranged in. a pattern such that between the relievingactionst. I the spindle is sustained by at least' two' bearing' elements. and'prefe'rably by four of the elements i disposed'on opposite sides of the spindle. The

bearing elements 20 are accordingly disposed in two circular groups arranged respectively to.

travel in paths coincident with the bearing tracks formed by the inner and outer rings 25 and 26 of the bearing member l5. In the particular congrooves. are arranged in apattern such that all oi, the, elements may register withvgrooyes, simultaneouslvin either of two. angular positions of the cagejl relative to the upper bearing member, said positions being spaced apart 180. In all otherpositions of the cage at least one pair and preferably two pairs of the bearing elements will ride-on a bearing surface intermediate a pair. of grooves and thus sustain the spindle. in its normal, or .projectedposition with respect to the quill 5., a 1

As the spindle 5 rotates, the bearing elements 20 rollover the bearing tracks and the cage 2! turnslatone-half, the speed of thespindle. Consequently, the bearin elem nts. register with the grooves ,oncein each revolution of the spindle.

As the elements enter the grooves 22, the thrust on thespindle 5 is momentarily relieved allowing the spindle to reoede slightly or dwell while the feeding ,movementpi the quill continues.v In climbing,..outoi the grooves, the bearing elements. act-to project the spindle axially relative to thequill untilgthe elements ride on the bear ing surfaces intermediate the grooves. .Such intermittent relief and projection of the spindle struction illustrated, four bearing elements 20 are provided in each group. The elements of each group in turn are arranged in pairs spaced apart approximately one hundred and twenty degrees,

while the elements of the pairs are spaced apart sixty degrees from each other. The bearing elements of the outer group are similarly spaced, 'but are oiTset sixty degrees with respect to the elements of the inner group, as shown in Fig. 2.

The grooves 22 in the rings 25 and 26 are located sov that theirspacing corresponds exactly with that of the bearing elements when the bearing ring 25 is turned to the active position shown in Fig. 3. Registration of the bearing elements 20 with the grooves may thus take place periodically as the bearing cage rotates relative to the upper bearing member. Such registration occurs only when the bearing elements and grooves are symmetrically alined and the bearing elements thus enter and leave their associated grooves simultaneously. Immediately preceding, during and immediately following such registration, all

bearing elements are in load sustaining position While the companion bearing elements pass over grooves other than the one to which they corree spond in the angular pattern.

When the outer bearing ring 26 is turned to the inactive position shown in Fig 4, the pattern of the grooves is changed so that at leasttwo of rotation of the bearing cage.

with the quill and the drilling operation is therefore performedin 'the conventional manner. It will be apparent from the foregoing that the invention provides a"drill"chip breaker 'of novel and advantageous construction. The new and improved bearing arrangement provided by the chiptbreaker reduces friction to a minimum while operating automatically to intermittently p'roject --}and relieve the tool "so 'asto break thachipcurls formed thereby. The 'provisionfor adjusting the chip breaker to an inactive position makes it especially adaptable for installation in a drilling machine as a permanent part thereof, as the machine may thus be used when desired in the con ventional way without requiring removal of the chip breaker.

I claim as my invention:

1. The combination with a nonrotatable axial- 1y movable quill having a spindle supported therein for rotation and for limited axial movement relative thereto, means yieldably urging the spindle in a direction toward one end of the quill, a thrust bearing limiting the movement of the spindle toward said one end of the quill, said thrust bearing comprising a race ring nonrotatably fixed to the quill, a race ring fixed to and rotatable with the spindle, and a series of antifriction bearing elements non-uniformly spaced apart about the axis of the spindle and interposed between said race rings, one of said race rings having a series of radially disposed shallow grooves in the face engaged by the bearing elements spaced apart similarly to the spacing of the elements for simultaneous registration with the respective elements whereby the thrust on said spindle is periodically relieved incident l to the rotation of the spindle.

2. The combination with a nonrotatable axially movable quill having a, spindle supported therein for rotation and for limited axial movement relative thereto, means yieldably urging the spindle toward one end of the quill, a thrust bearing limiting the movement of the spindle toward said one end of the quill, said thrust bearing comprising a race ring nonrotatably fixed to the quill, a

race ring fixed to and rotatable with the spindle,

and a series of antifriction bearing elements interposed between said race rings, a cage operative to retain said bearing elements in fixed nonuniformly spaced relation, one of said race rings having in its bearing engaging face a series of shallow grooves spaced apart similarly to the spacing of said bearing element, said cage rotating relative to said one race ring in response to the rotation of said spindle whereby to periodically aline said bearing elements with said grooves and permit all of the elements to simultaneously enter the grooves and thereby momentarily'relieve the axial thrust on the spindle.

3. The combination with a drilling machine spindle axially movable with and rotatable rela- 6 tive to a nonrotatable reciprocatory support, of a chip breaker including a race ring fixed to the support and, encircling the spindle, a second race ring mounted'on said spindle in opposed relation to said first race ring, said second ring being rotatable with the spindle, a series of antifriction bearing elements interposed between and engaging the adjacent faces of said race rings, a cage adapted to hold said bearing elements in predearotaterrelative t the spindleasupport as said bearingilelements roll over said'race ring-s, said first :race ring having in its :bearingfengaging face a series of radially; disposeddrop grooves spaced apart ,similarly $0", the spacing of, said bearing ielements,- said bearing elements being operative to sustain the spindle'against the cutting action zof the I drill imposed .;by' the feedmovements of the spindle support when engaging the face of .said first race ring and to momentarily relieve mthe axial thrust on the spindle upon dropping yinto -said grooves the langular spacing of said grooves and said bearing elements being such that registration, therebetween: occurs once only in each revolution of the spindle.

4. The combination with a nonrotatable axially movable quill having a spindle supported therein for rotation and for limited axial movement relative thereto, a chip breaker including a pair of annular bearing members mounted on said quill in concentric relation with their axial faces forming coplanar flat bearing surfaces normal to the axis of the spindle, an annular bearing member fixed to and rotatable with said spindle having one axial face defining a flat bearing surface opposed to said first mentioned bearing surfaces, two series of antifriction bearing elements interposed respectively between the bearing face of the member on the quill and the bearing faces of said concentric members, a cage holding the bearing elements of each series in predetermined angularly spaced relation, said concentric hearing members having in their faces radially disposed drop grooves, one of said concentric mem bers being rotatable relative to the other member to a position efiective to dispose the grooves in a symmetrical pattern corresponding to the spacing of said bearing elements in said cage whereby to permit all of said elements to register simultaneously with the grooves in the rotation of said cage and thereby momentarily relieve the spindle, said one member when rotated from said position acting to interrupt said relieving action.

5. The combination with a nonrotatable axially movable quill having a spindle supported therein for rotation and for limited axial movement relative thereto, means yieldably urging the spindle toward one end of the quill, a thrust bearing limiting the movement of the spindle toward said one end of the quill, said thrust bearing comprising a member fixed to the spindle presenting an annular bearing surface normal to the axis of the spindle, a pair of concentrically arranged members carried by said quill and jointly presenting an annular bearin surface spaced from and disposed parallel to the bearing surface of said first mentioned member, a series of antifriction bearing elements interposed between said bearing surfaces, a cage operative to retain said bearing elements in predetermined angularly spaced relation, said concentrically arranged members having radially disposed drop grooves in the faces forming said bearing surface, said grooves being spaced apart similarly to the spacing of said bearing elements and adapted to receive the elements in the rotation of said cage whereby to momentarily relieve the spindle, and means for rotating one of said concentric members relative to the other to position said grooves so that a predetermined number of the bearings are effective at all times to sustain the thrust of the spindle while the other bearings are in registration with the grooves.

6. A chip breaker for drill spindles comprising termined non-uniformly spaced relation and to two groups of antifriction bearing elements ar- V ranged in concentric series, a cage for holding said elements 'in' predetermined spaced relation, a

'gageable by both groups of elements, the hearing surfaces of said concentric members being interrupted by radially disposed drop grooves, the

grooves of each group being spaced apart so that by rotation of one of the concentric members relative to the'other they may be positioned to register with all of the bearing elements simul- "taneously.

ERIK HALLDEN.

REFERENCES CITED .Thei'ollowing references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,523,629 Bullock Jan. 20, 1925 2,430,019 Jenkins Nov. 4, 1947 

